Calorie calculator
Calorie calculator: how many calories do you need a day?
To find how many calories you need a day, estimate your resting energy with the Mifflin-St Jeor formula and multiply it by an activity factor. That gives the calories that keep your weight steady. This calculator also shows daily targets for losing or gaining about 0.25 to 0.5 kg per week. Results are estimates, not medical advice.
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Use the calorie calculator
How many calories should I eat a day?
It depends on your age, sex, height, weight and activity. A calorie calculator estimates the calories that keep your weight steady, called maintenance. Eat around that number to maintain, a little below it to lose weight gradually, or a little above it to gain. Use the result as a starting point.
How do I calculate my daily calories?
Work out your basal metabolic rate (BMR) with the Mifflin-St Jeor formula, then multiply it by an activity factor from 1.2 to 1.9. The result is your maintenance calories or TDEE. Subtract or add calories from there to lose or gain weight.
Men: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5
Women: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161
| Activity level | Factor |
|---|---|
| Sedentary (desk job, little exercise) | 1.2 |
| Lightly active (exercise 1-3 days a week) | 1.375 |
| Moderately active (3-5 days a week) | 1.55 |
| Very active (6-7 days a week) | 1.725 |
| Extra active (physical job or training twice a day) | 1.9 |
How many calories should I eat to lose weight?
A gradual deficit of about 250 to 500 calories below maintenance is a common choice, which is roughly 0.25 to 0.5 kg (0.5 to 1 lb) per week by the usual rule of thumb. Do not eat below 1,200 calories (women) or 1,500 (men) without medical supervision.
For a time-to-goal estimate, use the calorie deficit calculator.
How many calories should I eat to gain weight?
A modest surplus of about 250 to 500 calories above maintenance is a common starting point for gaining weight gradually, ideally with strength training. Larger surpluses mostly add fat. Track your weight for a few weeks and adjust, and speak to a professional if you are underweight.
Log what you eat in the app
A target only helps if you know what you eat. AI Calorie estimates calories and macros from a photo or a short description. It is free to start with daily limits: see pricing. This calculator is not medical advice; see medical review.
Sources
- Mifflin MD, St Jeor ST, et al. "A new predictive equation for resting energy expenditure in healthy individuals." Am J Clin Nutr 1990;51(2):241-247. doi:10.1093/ajcn/51.2.241
AI Calorie gives general nutrition information and AI-generated estimates. It is not medical advice. See medical review and our Terms of Use.